Search found 17 matches
- Mon Mar 20, 2017 6:35 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Saying Thank You to Dr. Lavelle
- Replies: 490
- Views: 513782
Re: Saying Thank You to Dr. Lavelle
Dear Dr. Lavelle, Since beginning college in your 14A class, I cannot express enough gratitude for all of the hard work you put in to this class. Throughout 14A and 14B, your organization, helpful review sessions, and endless hours of opportunities you have given students to expand their knowledge a...
- Sun Mar 19, 2017 11:40 am
- Forum: Reaction Mechanisms, Reaction Profiles
- Topic: Pre-Equilibrium
- Replies: 2
- Views: 551
Pre-Equilibrium
How do you determine which step is the slow one and which step is the fast one in your pre-equilibrium approach?
- Sun Mar 12, 2017 11:35 pm
- Forum: General Rate Laws
- Topic: quiz 3
- Replies: 2
- Views: 555
Re: quiz 3
Rate constants and equilibrium constants (k) do not have units. Thus, all of your units should cancel out in your equation.
- Thu Mar 02, 2017 6:36 pm
- Forum: *Electrophiles
- Topic: Neither electrophile nor nucleophile
- Replies: 2
- Views: 5312
Re: Neither electrophile nor nucleophile
Molecules that are neither nucleophile nor electrophile actually can exist. For example, methane(CH4) is neither an electrophile nor a nucleophile. The center atom of carbon has no lone pairs to share with a filled octet, and thus no interest in gaining electrons too. Each of the four hydrogen atoms...
- Sun Feb 26, 2017 9:06 pm
- Forum: *Organic Reaction Mechanisms in General
- Topic: Naming Organic Molecules
- Replies: 20
- Views: 4070
Naming Organic Molecules
Does anyone have any tips for naming complex organic compounds/molecules? Do we just need to memorize them or is there a better method? Thank you in advance!
- Sun Feb 12, 2017 1:20 pm
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: When to add Pt(s) to a cell diagram?
- Replies: 2
- Views: 608
Re: When to add Pt(s) to a cell diagram?
In a cell, metal is necessary in order to conduct electrons. When there are no metals present in your equation, you must then add a metal to your cell diagram. You would find Pt(s) in a cell diagram because there must have been no metals present without it. For example, you will not find Pt(s) in a ...
- Sun Jan 29, 2017 9:29 pm
- Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
- Topic: Homework.8.75
- Replies: 1
- Views: 482
Homework.8.75
For homework #75 in chapter 8, we are supposed to utilize bond enthalpies to calculate the reaction enthalpy of an equation. I understand how to do this for (a), but for (b) and (c), why do we only break and form 1 mol of the molecules. I understand that parts of the molecules in the products and re...
- Mon Jan 16, 2017 8:43 am
- Forum: Thermodynamic Systems (Open, Closed, Isolated)
- Topic: By or On the System? [ENDORSED]
- Replies: 4
- Views: 1003
Re: By or On the System? [ENDORSED]
According to the first law of thermodynamics: -The internal energy of an isolated system remains constant. -Work that is done on the system is positive and is written out like this: change in U = q + w . This means that W, the system, is positive, as well as the heat added to the system, causing a p...
- Mon Nov 21, 2016 11:53 am
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Kp and Kc
- Replies: 4
- Views: 932
Re: Kp and Kc
The difference between Kp and Kc is that Kc refers to molar concentrations and Kp refers to the partial pressures of gases in a closed container. They are both equilibrium constants of gaseous mixtures though!
- Sun Nov 06, 2016 9:53 pm
- Forum: *Molecular Orbital Theory (Bond Order, Diamagnetism, Paramagnetism)
- Topic: Chapter 4 Question #107
- Replies: 1
- Views: 1862
Re: Chapter 4 Question #107
bond order = (number of electrons in anti bonding molecule - number of electrons in bonding molecule)/2 (drawing lewis dot diagrams can also help you figure this out) a) the bond order changes from 2 to 1.5, creating a longer bond in the cation. C2 is diamagnetic. Species is paramagnetic due to the ...
- Sun Oct 30, 2016 10:56 pm
- Forum: Hybridization
- Topic: conceptual question
- Replies: 2
- Views: 687
Re: conceptual question
Hybrid Orbitals: 2e- pairs = sp 3e- pairs = sp^2 4e- pairs = sp^3 5e- pairs = sp^3d 6e- pairs = sp^3d^2 It is helpful to draw the lewis structure of the compound you are working with. Then, for each atom, count the number of electron pairs that it has. Once you have these numbers, then you can utili...
- Sun Oct 23, 2016 4:18 pm
- Forum: Dipole Moments
- Topic: Do Dipole Moments affect Bond Strength?
- Replies: 2
- Views: 3862
Re: Do Dipole Moments affect Bond Strength?
Electronegativity does in fact affect bond strength because the larger the difference in electronegativity between two atoms, the stronger their bond strength is in most cases. For example, Fluorine has a higher electronegativity than Chlorine; thus, the bond energy of HF is higher than the bond ene...
- Sun Oct 16, 2016 9:19 pm
- Forum: Properties of Electrons
- Topic: Mass
- Replies: 1
- Views: 445
Re: Mass
The mass of an electron can be calculated in grams (9.11x10^-28) or in kilograms (9.11x10^-31) when utilizing the mass in equation's like de Broglie's! You will just need to convert the grams to kilograms so that units cancel out properly in the equation.
- Sun Oct 09, 2016 4:03 pm
- Forum: General Science Questions
- Topic: constants/formulas
- Replies: 1
- Views: 687
constants/formulas
Does anyone have a list of constants/formulas that they feel we should know for quiz #1? I'm trying to put together a list to memorize but I feel like I'm missing a few! Thanks!
- Sun Oct 09, 2016 3:49 pm
- Forum: Student Social/Study Group
- Topic: Post All Chemistry Jokes Here
- Replies: 9651
- Views: 3006436
Re: Post All Chemistry Jokes Here
Q: Did you hear oxygen went on a date with potassium?
A: It went OK...
A: It went OK...
- Thu Sep 29, 2016 2:36 pm
- Forum: Photoelectric Effect
- Topic: Wavelength vs. Photons [ENDORSED]
- Replies: 5
- Views: 1258
Re: Wavelength vs. Photons [ENDORSED]
-photons are basically particles of light/a quantum of light that travel at the speed of light in empty space too (because their mass is nonexistent - when they're emitted from an atom their mass is 1/2 positive from proton and 1/2 negative from electron --> mass of zero) -photons carry energy that ...
- Thu Sep 29, 2016 2:17 pm
- Forum: Student Social/Study Group
- Topic: Dykstra Hall Study Group (Fall 2016)
- Replies: 25
- Views: 3491
Re: Dykstra Hall Study Group (Fall 2016)
Hey everyone! I'm down to join too! I'm on the 4th floor! My email is: amberecarlton@gmail.com :)